Tech companies have been worse than firms in other sectors at monitoring the number of women they employ, which makes analyzing changes in gender diversity “almost impossible,” writes Thomson Reuters’ André Chanavat in his analysis.

Just nine tech companies out of 254 shared data on the share of their total workforce and management team that was female in 2005 and 2010.

“[W]hile there is only a relatively limited pool of data available from the technology sector, it nonetheless appears to signal that these companies have made less progress at helping their employees smash through the glass ceiling,” Thomson Reuters’ report reads.

The company’s analysis suggests that the frequency with which women enter management positions in tech firms is actually declining. This was true for Intel, where the share of female managers dropped from 30% in 2005 to 15% in 2010.

Catalyst’s study tracking return on sales, return on invested capital and return on equity found that companies with at least three female board directors delivered better financial performance than companies with only a few women on their boards.

“We are disappointed that the Facebook board will not have any woman members,” CalSTRS’ director of corporate governance Anne Sheehan wrote. “This is particularly glaring at a time when there is clear evidence that companies with diverse boards perform far better than the companies with more homogenous boards.”

About the guest blogger: Bianca Bosker is the Technology Editor of the Huffington Post. Her work has appeared in the Wall Street Journal, Far Eastern Economic Review, Fast Company, Conde Nast Traveler, and the Oregonian, among other publications. She is the co-author of a book on the cultural history of bowling entitled Bowled Over: A Roll Down Memory Lane and a graduate of Princeton University. You can contact her at Bianca AT huffingtonpost.com and visit her website. Follow her on Twitter at @bbosker.